The condition is increasing in incidence, in part as the result of women postponing pregnancy until they're older and less likely to conceive. There are other possible causes, but unexplained infertility still accounts for up to 10% of all cases. Artificial insemination is often used to treat unexplained infertility.
Bald eagles are a North American species that historically occurred throughout the contiguous United States and Alaska. The largest North American breeding populations are in Alaska and Canada, but there are also significant bald eagle populations in the Great Lakes states, Florida, the Pacific Northwest, the Greater Yellowstone area, and the Chesapeake Bay region. Adult bald eagles have the dark brown body and distinctive white head and tail. In contrast, juvenile bald eagles have mottled brown and white plumage.
As with many raptors, females are larger than males. The bald eagle is Alaskaâs largest resident bird of prey with a wing span of up to 7.5 feet (2.3 m) and weight between 8 to 14 pounds (3.6 â 6.4 kg). Found only in North America, bald eagles are more abundant in Alaska than anywhere else in the United States. The Alaska population is estimated at 30,000 birds.